Mon 19 January 15 -The Begining of Life
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Transcript Mon 19 January 15 -The Begining of Life
Izben C. Williams, MD, MPH
Instructor
9/15/2014
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Developmental Journey
There are immensely complicated, mysterious, and
beautiful transformation (biological, psychological
and social) that take place between conception
and old age
The period from CONCEPTION TO BIRTH sets
the stage for all other development that we
undergo as humans
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Some Prenatal Influences I
Genetic factors play a prominent role in
determining the biological potential of a fetus.
The process of development is a sequential
unfolding of normal events (and disorders) that
are genetically determined
In about 40% of children with ADD heriditary
factors are the basis
Down syndrome (trisomy 21), Klinefelter syndrome
(XXY) and Fragile X syndrome are also genetically
determined conditions
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Some Prenatal Influences II
Sex and survival factors:
At conception 160 M : 100 F
At birth the ratio is aprox. 100 M : 100 F.
The surviving males have a higher risk for some degree
of brain dysfunction
ADD ten times more frequent in males
Gestational age, birth-weight, maternal health, and
perinatal factors may predict outcome
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Intrauterine Influences on
development I
The intrauterine environment can significantly
affect fetal brain development, and hence all
future actions (behaviors)
Animal models used to mimic adverse intra uterine
conditions in humans
Intrauterine insults to the brain may be acute or
chronic
9/15/2014chronic
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Intrauterine Influences II
Even brief periods of hypoxemic compromise can
have significant effects on the fetal brain causing
neuronal loss and cerebral white matter damage
Subtle brain injury can occur, for example to a
particular class of neuron, and this can have a
significant effect on the function of a specific system,
(eg hearing, vision)
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Intrauterine Influences III
Chronic mild placental insufficiency can result in
long term deficits in neuronal connectivity
Repeated acute exposure to an inflammatory agent
results in diffuse subcortical white matter damage
and in some cases periventricular necrosis.
The timing and severity of these prenatal insults
determines outcomes, in terms of the severity of the
damage and the regions of the brain affected.
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Smoking and Alcohol
Placenta mediates fetal growth and influences
long-term health
Placenta to birth-weight ratio is regarded as an
indicator of the quality of placental function
Maternal prenatal smoking and alcohol
consumption may influence fetal growth by either
directly or indirectly altering the function of the
placenta, and hence the development of the fetus.
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Role of the placenta in fetomaternal exchanges
Reminder of placental role:
Exchange process via membranous exchange
mechanisms
The fetal lung
Nutritive and excretory functions
Protective function and Immunological barrier
Endocrine function and protein transfer
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Some noxious trans placental
influences
Some microbes can cross the placental barrier
despite its efficiency:
Sexually transmitted diseases (treponema
palidum, HIV, Neisseria Gonorrhea
Feto-toxic infections (rubella, toxoplasmosis,
cytomegalovirus, herpes simplex genitalis)
Drugs (most antibiotics, corticosteroids,
teratogenic drugs such as Roacutane and
Thalidomide
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Neonatal Capacities
At birth, the infant is pre-adapted to be cared for
by the mother by the presence of attachment
behaviors.
Initial attachment behaviors (eg. crying and
clinging) increase the likelihood of maternal care
and assist the infant in attaching to the mother
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Neonatal Capacities
The neonate possesses a number of innate simple
reflexes
1. Moro reflex or startle reflex: flexion of
extremities in response to sudden stimulation
2. Palmar grasp reflex
3. The rooting and sucking reflexes (both aid in
feeding the infant
4. The Babinski reflex
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Development Sequences
Key: Consult table in text for schedule of motor,
vocal, and sensory development sequences of
the infant
Cognitive maturation: by age 18 to 24 months a
child is capable of elementary trial-and-error
reasoning.
For example a child will attempt to place a square
object into a square opening of a form box after
trying to insert it into the circular and triangular
opening
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Birth and Post-partum
Two separate patients: Mother and Infant
Infant status
APGAR
Primitive reflexes (Startle, sucking, grasp, Babinski)
Maternal status
Physical status
Psychological status
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Theories of Development
Several theories, derived primarily from clinical
experience and experiment.
Perhaps the best known systems in use today, are:
Freud’s psychoanalytic theory,
Piaget’s Cognitive developmental stages
Ericson’s Psychosexual stages
The theories mostly identify developmental
landmarks
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Concepts of Child Development
There is a lawfulness to all natural development,
which serves as a framework within which we can
assess and understand children and adults
Epigenesis: The development of an embryo from
the successive differentiation of an originally
undifferentiated structure (Epigenetic= after genes)
Physical Epigenesis
Behavioral Epigenesis
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Developmental Tasks
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Multiple developmental tasks
The pre-school child traverses several motor,
social, and verbal/cognitive developmental zones
by age six.
Key: See schedule of age-related developmental
tasks, in text. Important to have an appreciation
of these milestones
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Developmental Screening
There are many Developmental Screening-andAssessment (S&A) Instruments for young children
ages birth through five years
Link to S&A instruments:
http://www.nectac.org/~pdfs/pubs/screening.pdf
These instruments emphasize Psychological,
Social, Emotional and Physical Development
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Psycho-Social Development I
The principle psychological task of the first year of
life is the formation of intimate differentiated
attachment to mother of caregiver.
Failure of the infant to develop this specific early
attachment may result in later defects in the
capacity for empathy and for close warm reciprocal
relationship.
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Psycho-Social Dev’nt II
The social smile is an early marker of the beginning
development of a specific differentiated relationship,
as are the preferential vocalization, visual pursuit and
anticipatory gesturing of the 5-month-old infant in the
presence of the mother
Endogenous smiling develops from an innate reflex
response at birth
Exogenous smiling a response to the form of a face – 8
weeks
Preferred social smile a response to mother’s face 16
weeks
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Psycho-Social Dev’nt III
Stranger anxiety begins at ~ 8 months
Object relations (psychoanalytic theory)
Response to Maternal deprivation/separation
Play: its role and significance
Autonomy and self awareness
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Psycho-Social Dev’nt IV
Sociocultural factors:
Innercity: increases risk of psyc. disorders
ADD: twice as high in low income families
Psychosocial, or sociocultural, retardation:
deficient language, speech and cognitive skills
associated with relative deficiency in adequate early
stimulation (usually lower socio economic class)
Weaning from bottle shorter in middle class
toilet training favors lower class
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